Electrotherapeutic apparatus



Feb. 2 1926. 1,571,508

- w. L. CARLSON ET AL ELECTROTHERAPEUTIC APPARATUS Filed March 24, 1921 2 Sheets-Sheet l Feb. 2 1926. 1,571,508

W. L. CARLSON ET AL.

ELECTROTHERAPEUTI C APP-RATUS Filed March 24, 1921 2 Sheets-Sheet 2 Fregaoe Czcrren I Patentecl Feb. 2, 1926.

UNITED STATES PATENT OFFICE.

WENDELL L. CARLSON AND GLENN W. CARPENTER, O]? WASHINGTON, DISTRICT Oli COLUMBIA.

ELECTBOTI-IERAPUTIC APPARATUS.

Applica/don filcd March 24, 1921.

Ve tknmvn tbut we, \Vuumu.n L. CARLSON and (ILENN W. CARIEN'IIGR, ctzvns of (ho Unilod States, rvsiding :1t \Vnshiugton, Dishict o'i Columbia, buvo invvutod cortan new :md useful Improvoumnis in Electroizherupouic Appamtus, of wbcb tbo followiug is a sywcficuton.

Our uvonton rolutog broudly to un uppamtus fm. o.ectrcally produoug bonnficial effects in the body aud moro purticuzuly to eleotrotherapoutic apparatus in Which thermionic vacuum tubvs are cmployed in the production of bg'h froquoncy oscillatons at a frequency abovo tbut whch cf'fects the norvous system of the body.

Tbe object of the inventon is to provide un eloctrotberapeutio equpmont iucluding vacuum tube oscillators Wbch may be operated from sourccs of atcrnatng current of commercial frequency and which requires no special generators heretofore necessary in this form of equipment.

Another object of our invention is to pro- Vide means or increasing the amplitule of oscllations developed by vacuum'tube electrotherapeutic apparatus and applying thishigh frequency current to the body of a patint.

A furthcr objcct of the invention is to provide moans fo1 opcration of cloctrotbempeutc apparntus on polypbase supply circuits for the developmont of high froqucncy oscillations.

Othcr and furthcr objects of tbo inventon willbe clear from the speofication following and by reference to the accompnnying drnwi ngs in Which;

Figure 1 sbows a vacuum tube oscillator having the high frequency anode circuit connected dreotly to the operating electrode and suppliod with an alternatng ourront source of commercal frcquency.

Figure 2 shows a vacuum tube oscllutor having a capacity back coupled crcuit and un iron core high froquency output transformer.

Figure 3 sbows un equipme-nt in whch on tubo operates as an osollutor and tbo otber tube as an amplifier.

Figure 4 shows two tubes oporating in paralel, and

Figure 5 s a crcuit arrangeme-nt for th1ce tubes operated from a three phase source of current.

Serial No. 455,106.

Reforriug particuarly to tbo d r:uvings tbo om:uit in Figura 1 includos power tubo lv buving ibs grid element l oonnocted tbrougb inductunce 36 and capacity 63 io tbo catbodo or filamcnt 1". The hgb resistuuco shunt 4 gvos the proper bas voltago lo tbo grd 1. Tbo trunsformor 7 bus hvo svcoudury windiugs, 19 aud 20, wndng 1?) to stop-up tho voltugc ior tbc unodo 1" or plnto circut potential and the windng 20 Lo stop-down the voltage to supp]y tbo filmnont ourrcu. Tho primary winding 01" trunsformor 7 in onergized f rom 2L, source of altcrnatng curront of commeroal frequoncy. boko col 6 prevents the secondary 19 and 20 from shorting the high frcquoncy pluto crvut consisting of capacity 5 und induotuncc S. Vindings 36 and 8 in the grid nud pluto circuitS respectvely are iuductvoly couplod providing the hgh froqucucy feod bnck pulb between the circuits. Tbe bgh froqucncy currents developed by thoso crcuts are upplied to the patients body by olootrodo. 9. The electrode"9 '1s C0nuoctod to one 0nd of coil 8 and forrns one elomont of 2L condonsor a'cting through the medium oi tbo putonts body in conjunction Wlb tbo groundod opposito terminal 10 to gvo tbo rcqurod cupacity shunting coil 8 to provide a rvsonnnco Circuit.

In Figure 2, rofvreuco obnmvior 1 indicatos a bgh powm vacuum. tubo counociod to un assocaiod osculihg crcut vonsisting of output bgb froquvnvy truusl'ormcr 11 shuntod by vurubo. cupzxctos 23, 24 und 25. Tbe common tm-mnul of cupuctios 24; and 25 is couueciod to tbo lvud fxom filament 1 of tubo 1. Capacity (3 joins ono end of tbe oscillatn;r crvut to tbo g1'id oloment 1 of tube 1; Tbc higb voltugo svcondury winding 19 of tbc tmnsformor 7 '19 connocted in che p1ate circut botweon tbo plato element 1 of tubo 1 and tbe filumont 1". The otho r end of tbo oscllating: crcut connects to tbc lowcr terminal of wndnp; 19. Fila- 1nent curront is suppliod tbrougb stopdown tr:msformor wiuding 20 on translormor Ressfnnoo. 4 gvcs bas grd potoutul. Iud oloctrodos 28 md 29 supply tbo bigb frequonoy currout to the putionts body tlnu the ndjustablo transformer 11 hnving an iron core.

n Figure 3 tbo tubo 1 is ussocntcd wth inductance 86, capacty 63 and resstance 4 in its grid circut. Inductance 30 in plate oircuit s coupled lo induotance 36 and shunted with tuning capacity 31. Plate voltage is supplied through transformer 7. A high frequency path is provided tbrough condenser 12 shuntin hi h vo1ta e windin b b b b tained from transfonner 7 through choke coil 6'. A11 iron core hgh frequeney output transforxner in series with condonser 13 15 connected across the plate 14 and fila- 1nent 14 of tube 14. The output terminals may be applied for electrical treatment of a patients body inany of the the Wellknown methods. V

Figure 4 illustrates a method of utilizing both halves of the cyeles of the low frequency plate cur1ent supply. The plates 1 and 2 01 vacuum tubes 1 and 2 respectively are associated with inductarees 34 and- 35, respective- 1y, and supplied with high voltage alternati1ig current by means of the high potential secondary winding 19 of the transformer 7. Capacities 38 and 39 are connected in shunt to the inductances 34 and 35 for tuning the circuits to certain definite wave lengths. The grids 1 end 2 of' tubes 1 and 2 are connected in parallel and the circuit coupled to coils 34 and 35 by means of the-coil 36. Capacities 37 and 40 serve as radio frequency by-passes around the high voltage winding 19 of transformer 7. Capacity 63 serves as a radio frequency by-pass around the grid biasng resistanee 4. The filaments 1" and 2 are heated by energy supplied by winding 20 of transformer 7. Coil 43 is coupled to the output coils 34 and 35 of the oscillating eircuit. Electrodes connected to this coi1 11 in any of the well known methods may be used for electrotherapeutic purposes. This circuit supplies radio frequency oscillations modulated at double the frequency of circuits shown in F igures 1, 2 and 3.

Figure 5 illustrates a method of 'using polyphase alternating current as plate supp1y to vacuum tubes 1, 2 and 3. The 1ow frequency transformer 7 in this diagram consists of the primaries 16, 17 and 18, and the high voltage secondaries or plate supplied windings 44, 45 and 46 connected with plate electrodes 1, 2 and*3. The filament currents for heating filaments l", 2 and 3 are supplied by the step down transformer 51 to the ooil 36, whioh provides means of coupling between the output and input of the tubes. Capaeity 63 is a radio frequenoy bypass around the grid biasing resistance 4.

Electrodes may beeonnected to the ternfinals of coil 43 coupled to the output cireuit 52 and the high frequeney eurrent used in any of the well known methods 0f bodily lreatment. k

The operation of the cireuits is as follows: In Figure 1 the transformer 7 is supplicd with a source of 10W frequency connuereinl alternating current. The filament is heated to incandescence by current supplied from winding 20 of trahsformer 7. Positive anl negative voltages are alternately impressed on the plate element 1 01' the tube. Only on the positive half of the eycle is the tube operative. Under these c0nditions, local oscillatons are produced' and sustained by means of the couplings between coils 36 and 8. A resonance voltage across inductance 8 Will rise to such a va1ue at the electrode terminals as to produce what is known as the Tesla current effeet.

In Figure 2 thehigh frequency osoillations are sustained by means of the capaeity couplin'g ratios of condensers 24 and 25. The

voltag at electrodes 28 and 29 can be varied by adjusting the secondary turns of transformer 11.

In Figure 3'the associted eircuit with tube 1 oscillates at its natural period determined by inductances 36 and 30 and associ ated capacities. These high frequecy oscillations are impressed on the grid 14 of tube 1 14 and hence niodulates the 'low rquency plate current. The circuit zissociated with tube 14 inereases the amplitude of the 05- cillations developd by tube 1. The amplified high freque'ncy current at secondary terminals of transformer 11 is adaptable or eelctrotherapeutic treatments.

The circuit inFigure 4 oseillates at a, frequency determined by the inductanee and the capacity of the output 'circuits 35, 39, 34 and 38. Oseillations ar'e sustained by means of the coupling between the grid coil 36 and coils 34 and 35. Radio frequency oscillations will be modulated at double the frequeney of the late supply; The output delivered to the t erapeutic electrodes may be varied by changing the c0upling between coil 43 and the coils 34 and 35.

In Figure 5 oscillations are sustained by the eoupling between grid coil 36 and output coil 52. Energy delivered to electrodes through coil 43 may be varied by Changng the coupling between coils 43 and 52. There w111 occur an overlapping of 1ow frequency modulat1ons so that a sustained high frequency oscillation will result. The osilla-- tions devel'oped in the electron tube cireuits have sueh a frequei1cy. that no bodily sensation is produced other than dathermc.

\Vhile We have described our invention in certain specitic cmbodiments, we do not intend any limitations beyond the scope of the appended cluims.

1. A11 clectrothempeutic apparutus comprising in combination a source of alternating current of relatively loWfrequency, a thermonic eloctron tube havng 2m anode, calhode. and ,Q1'd elcctrode, un input circuitincludiug suid c'uthode nd grid electrodc, an output circut including said anodo und g1'id c-ect1ode, said circuits boing electrically inteflinked for the production of alternating cmmu't of relatively high frequency at which 1m bodly sensation is produced othe1 thun (Huthormc and a high frequency electrode c-onuected -wi th said output circuit tor impressng suid high frequency currents on the body of a patient.

2. An electrotherapeutic apparatus comprising in combinatin a source of alternatng current of relatively 10W frequency, a thermionic electron tube, having a cathode, anode and grid electrode, un input circuit interconnecting said cathode and grid e1ectrode, an output circuit interconnecting said anode and grid electrode, a transformer baving primary and secondary windings, with its primury Winding connected with said sour ce of alternating cunent and its secondzu-y Winding connected between sad anode and cathode, said input and outputnitcuits being electrically 'coupled for inCreasing tho frequency of the alternating c.urrent derived ir'om said source to a frequency at Which no bodily sensation is produced other than diathermic, and a high frequency electrode connected with sad output circuit for impressi.ng said high frequency current on the body of a patient.

3. A11 electrotherapeutic apparatus comprising in combination a source of polyphase 10W frequency current, a plurality of electron tubes each having a cathode, anode and gri d electrode, said tubes corresponding in number With the number of phases of S2Lid OW frequency current, means for impressing one phase of said polyphase source upon each of said anodes, and a, circuit interlinking said grid electrodes with each of said unodes for increasing che frequency of said source to a frequency at which no bodily sensation is produced other than diathermic, a high frequency electrode, and means comrmon to each of said anodes for impressing high frequency currents i1'pon said high frequency electrode fo application to the body (.f a patient.

4. An electrotherapeutio apparatus comprising ii combination a source of relatively lo frequency alternating currcnt, un oleotrou tube having cathode, anode and grid electrodes, a connection between said anodc zmd cathode to said source of low frequency alternating current, a, circuit interhnking said gl'id and cathode tor increasing the frequency of said source of relatively low frequency alternuting currentto a frequency ut which no bodily sensation is produced other than diuthermic, and a high frequency ul .ctrode connected With suid anode whereby high frequency encrgy inay be impressed upon the body of a putient.

5. An electrotherapeutic apparatus comn.si11g in combinztton u source of relatively i nv qucnoy ulternating cunent, a plurality o clectron tubes each having cathode, uuode and ,qrid clectrodes, a transformcr in- (luding a. prnnury winding and a pluralit v of secondary windings, an input circuit including each of sad grid electrodes, a pair of output circuits independently counected with each o" =:Ed anodes,'one of said secondary windngflbaing arranged to heat the cathodes of a of said tubes and the other of snid secondm-y windings being arran'ged to supply current to each of said independent output circuits, a con'nection between said input circuit and a point on sad first mentioned secondary winding fo1 deriving a negative bias for said g1id electrodes, said input and output circuits being mutually electrically coupled for the generation of oscillations at a, frequency at Which no bod- 1ly sensation is produced other than diathermic, and means coupled with said output circuits for impressing said high frequency oscillations upon the body of a patient. i

6. An electrotherapeutic ,apparatus comprising in combination a source of relatively low frequency alternating current, a plurali1y of electron tubes each ha'ving a cathode, anode and grid' electrode, an input circuit interconnectng said cathodes and said grid electrodes, independent output circuits interconnecting said anodes and cathodes, each of said circuits including a.n inductance, said inductance being electromagnetically coupled, means fo-r impressing said alternating current on each of said output circuits for actuating said electron tube c ircuits for the multiplication of the ,frequency of the source to a frequen cy at Whch no bodily sensation is produced other than diathermic, zmd an ii1ductance electromagnet-ically coupled with said aforementioned inductances tor transferring the high frequencyoscillations thus produced to the body of a patient.

GLENN W. CARPENTEIL WENDELL L. CARLSON. 

